TACOMA — In the end, the 250 letters of support, an impassioned plea by her mother and Briana Waters’ own tears did not spare her from prison for her role in the 2001 arson of the University of Washington’s Center for Urban Horticulture.

The 32-year-old Californian was sentenced Thursday to six years in federal prison and ordered to pay $6 million in restitution by U.S. District Court Judge Franklin Burgess, who also declined her lawyer’s request that Waters be released on her own recognizance pending appeal.

The sentence followed weeks of drama, during which Waters fired her two public defenders and then hired attorney Bob Bloom only to ask that he not attend the sentencing because she was “angry at how he treated the court.”

Waters also asked the court for mercy on behalf of her 3-year-old daughter. “I don’t want to be a martyr to any cause. My cause is to take care of my family.”

Many of the letters submitted in support of Waters suggested that she had been wrongfully convicted. However, Burgess said he read them all and wondered “how they could know … these things.”

Waters, a violin teacher, is one of five activists alleged to have participated in the UW arson, which prosecutors say caused more than $6 million in damage while destroying rare plants, books and years of research.

She was convicted of two counts of arson, but not of other charges, including the use of a destructive device in a crime of violence, which carried a 30-year mandatory minimum sentence.

In discussing the case with jurors after the verdict, First Assistant U.S. Attorney Mark Bartlett said some jurors had said their not-guilty vote on the other charges reflected their sympathy for Waters.

Waters was the first of 18 suspects indicted on charges of involvement in the Earth Liberation Front, a militant Northwest underground group that between 1996 and 2001 claimed it carried out more than a dozen acts of arson and sabotage against targets deemed a threat to the environment or animals.

Damage was estimated in the tens of millions of dollars. Targets included a slaughterhouse, timber-company headquarters and a ski lodge at Vail, Colo.

While Waters’ attorney sought a prison sentence of five years with three years suspended, the government sought 10 years in prison, including extra time for terrorism — which alone could have added 30 to 40 years to her sentence.

At Thursday’s sentencing, another attorney representing Waters, Neil Fox, asked the judge to look at his client “not as a representative of the Earth Liberation Front, but as a person,” with a small child who would suffer if separated for a long time from her mother. “Sometimes … we get anesthetized to the human cost of incarceration.”

In addressing the court, Bartlett said Waters failed to take responsibility for her actions or to admit guilt and showed such a “sense of arrogance and entitlement in the case it would almost be comical if it wasn’t so serious.”

Twelve other people have reached plea agreements with prosecutors, and, according to court documents, their sentences are expected to range from probation to 13 years in prison.

Those reaching plea agreements included two women — Jennifer Kolar and Lacey Phillabaum — who assisted in the UW arson, and were key witnesses for the prosecution at Waters’ trial.